Head to head track comparison between stock i4 and stock v6

[Steve24]

What we really need is for some people to just understand that 90% of the difference is the gearbox.
I don’t know how many times this needs to be said.

Old fashioned six speed manual vs seven speed DCT.

More ratios plus way faster gearchange is obviously going to be faster.

The trade off for those who drive the manual is more driver engagement.
Most people who bought the V6 understand and accept that (hopefully).

I’d be willing to bet that actual in gear acceleration is very similar and likely comes down to seven ratios compared to six.

 

[Adam Brouillard]

Yes, a significant portion of the difference is the gearbox although the redlines also have a big impact here because this is related.

I looked at some dyno charts on the GRP website and assuming they are comparable, the power curves look quite similar after 2500 rpm and have similar peak power rpm. The i4 has a bit of an advantage throughout, but not enough to explain the performance difference. The i4 actually has 8 gears and closer ratios and so when it shifts at its 7200 rpm redline which is past its peak power it's going to stay very centered around this power peak as it accelerates up through the gears. This is on top of the time saved from the faster shifts.

The v6 power peak is right at its redline and it will also drop lower in the rev range with each shift with its wider spaced ratios. This means that it's not going to stay centered on its power peak as well and is going to be putting out a good bit less power and therefore torque at the wheels than the i4 at most speeds as it accelerates up through the gears.

These cars are actually a good example of how just looking at peak power numbers for an engine doesn't give a full picture. I go into more detail how all this works in the article I linked earlier.

For the record, I'm not saying this means the I4 is "better." Everyone can obviously make their own decision as to what they want out of a car. I'm simply providing some factual info which is often sorely lacking in public message boards.

 

[Lotus64]

I think we all agree that the I4 has more track potential vs. the V6.

The real question is how much more? Several posters have commented that they've witnessed similar performance between the two at the track with different drivers, and that has been my observation, based in real life experience, not theoretical discussion based on speculation and unrealistic data.

The I4 has the edge, but it's not much. Without an unrealistic launch and rollout, it accelerates at similar rates to the V6, eventually starting to slowly pull away above 60. The V6 doesn't have to deal with turbo lag, power drop off or constant shifting, which keeps it competitive.

A couple tenths in acceleration doesn't amount to much on a track vs. driver skill. If ultimate track time is the goal, the I4 is the answer. Yet if you're a capable driver, it's a non factor, as the V6 will easily keep up with the I4, which has been my experience.

 

[geoffbland]

I drove the V6 and the i4 back-to-back on my test drives. This of course was on the road and it has been years since I've done any track time.
But the i4 was noticeably faster. When you are pushing on it does keep the revs right in the power band. I don't know how long it takes to change gear in the V6 but I would guess 1/5+ of a second - against the 1/10 of a second for the i4. If you are really wanting the car for maximum lap times on track you should get the i4.

I still bought the V6 but it was a way closer choice between the two than I had expected before my test drives.

 

[RoryBellows]

With the same driver the i4 will be faster on a track. The faster gear changes with more gears will allow you to brake later and accelerate out faster of every turn. 0-60s are not different enough to make up for that.

 

[kitkat]

I doubt you'll ever get an answer to this question, the car has been out for a long time now and interest is waning. You need a consistent driver familiar enough with the Emira to test both stock cars back to back on a day with similar conditions, if it was going to happen it would have been done by now. Does such a driver exist on this forum? Probably not. Instead it's just going to devolve into DCT vs manual, 0-60 times, 70-100 times etc etc.

In the end I don't think the power delivery is going to matter drastically all that much in lap times, the cars have similar weights, similar power, similar handling and you spend most of your time with partial or off throttle at the track, that's the point right, you spend more time entering, holding steady or exiting corners than you do in wide open throttle straights.

 

[Adam Brouillard]

Approximately 50-75 percent of a lap is typically spent at full throttle depending on track layout and car type. Assuming the car is driven well, anyway.

I also checked and the I4 reaches 2800 rpm (full boost) at about 9 mph in 1st gear.

 

[Beachbum]

Isnt there someone with 2 Emira's on this forum, one V6, one I4?
Maybe he can offer to provide the service

 

[Rayjoedef]

Isnt there someone with 2 Emira's on this forum, one V6, one I4?
Maybe he can offer to provide the service

Yes, wiz....he knows the answer and so does every US turbo owner...

 

[Orchardbike]

Only way to finally get an answer is a race track shootout! What could possibly go wrong……

 

[Lotus64]

But the i4 was noticeably faster. When you are pushing on it does keep the revs right in the power band. I don't know how long it takes to change gear in the V6 but I would guess 1/5+ of a second - against the 1/10 of a second for the i4. If you are really wanting the car for maximum lap times on track you should get the i4.

The I4 will feel significantly faster than the V6 because the power is much more accessible in the middle of the range, in contrast to the top of the range for the V6. The V6 needs to be revved out to stay in the power band.

It's the same reason diesels feel so quick regardless of output. It's the drastic midrange punch. I4 is easy speed, V6 makes you work for it but stays competitive if revved out, ultimately giving up some tenths.

Yes, wiz....he knows the answer and so does every US turbo owner...

Only those with actual track experience know the answer... Those opinions actually carry weight in this discussion.

 

[Rayjoedef]

The I4 will feel significantly faster than the V6 because the power is much more accessible in the middle of the range, in contrast to the top of the range for the V6. The V6 needs to be revved out to stay in the power band.

It's the same reason diesels feel so quick regardless of output. It's the drastic midrange punch. I4 is easy speed, V6 makes you work for it but stays competitive if revved out, ultimately giving up some tenths.



Only those with actual track experience know the answer... Those opinions actually carry weight in this discussion.

Really? There's so many different track configs that may benefit one variant over the other....that's why I'd like an official ring time for both variants just like every other serious sports car brand.

 

[Adam Brouillard]

It would be pretty easy for most to feel the difference in acceleration, but to see how this translates to track times you would need a very high level driver and a dedicated test. Unlikely to happen.

It's pretty obvious based on the numbers we have that the I4 would be faster in that test, but by how much we will probably never know, and also... who cares.

Most people are only using this for track days where you are only racing against yourself, and the vast majority of people are limited by their skills, not the car anyway. Passing another car or getting passed is meaningless unless you know they have the exact car and setup as you. Just get whichever version appeals to you and try to learn and go faster each time in that one.

 

[Rayjoedef]

It would be pretty easy for most to feel the difference in acceleration, but to see how this translates to track times you would need a very high level driver and a dedicated test. Unlikely to happen.

It's pretty obvious based on the numbers we have that the I4 would be faster in that test, but by how much we will probably never know, and also... who cares.

Most people are only using this for track days where you are only racing against yourself, and the vast majority of people are limited by their skills, not the car anyway. Passing another car or getting passed is meaningless unless you know they have the exact car and setup as you. Just get whichever version appeals to you and try to learn and go faster each time in that one.

There is a track video by an Italian gentleman that supports the turbos better times....that said, that track looked short and may have benefitted the dcts short ratios.

 

[kitkat]

Yes, wiz....he knows the answer and so does every US turbo owner...

Yeah Wiz isn't going to be tracking, I've driven both of his cars and borrowed his i4 for two weekends.

 

[Adam Brouillard]

The I4 will feel significantly faster than the V6 because the power is much more accessible in the middle of the range, in contrast to the top of the range for the V6. The V6 needs to be revved out to stay in the power band.

It's the same reason diesels feel so quick regardless of output. It's the drastic midrange punch. I4 is easy speed, V6 makes you work for it but stays competitive if revved out, ultimately giving up some tenths.



Only those with actual track experience know the answer... Those opinions actually carry weight in this discussion.

This is not true, as I explained the real reason for the difference in performance earlier. The powerbands are very similar between about 2500 and peak horsepower.

 

[Adam Brouillard]

There is a track video by an Italian gentleman that supports the turbos better times....that said, that track looked short and may have benefitted the dcts short ratios.

Every track benefits from closer spaced gear ratios.

 

[StopLoss]

In multiple videos, the 400hp I4 (and you guys have to quantify 400hp or 360hp) is a solid one full second 0-60; sometimes 1.1 or even 1.2 seconds faster. Percentage and butt-in-the-seat feel wise, it's huge.

Here's a good video by a guy that knows what he's doing. I4 vs V6 in real-world usage. Good video:

 

[Lotus64]

Most people are only using this for track days where you are only racing against yourself, and the vast majority of people are limited by their skills, not the car anyway. Passing another car or getting passed is meaningless unless you know they have the exact car and setup as you. Just get whichever version appeals to you and try to learn and go faster each time in that one.

Now this, I agree with.

In multiple videos, the 400hp I4 (and you guys have to quantify 400hp or 360hp) is a solid one full second 0-60; sometimes 1.1 or even 1.2 seconds faster. Percentage and butt-in-the-seat feel wise, it's huge.

Again 0-60 is irrelevant to track performance. Let's get some first hand accounts with track experience to chime in, as opposed to qouting figures and other people's opinions.

 

[BruceN]

So I'd love to see the same capable driver race both on a track. Even a side by side 0-100mph would be great.
Driver skill clearly so much more important, but the i4 should be slightly faster due to DCT vs manual, slightly stronger torque curve, and slightly lower center of gravity. I'd love Car and Driver to do both on their Lightning Lap, but they haven't even done one yet